The light-bulb dummy load has been used with HF transceivers from way back in the old days (and sometimes more recently). Also, the Lightbulb QSO Party promoted the use of light bulbs as antennas.

I wanted to find out if I could do the same thing with a 5W handheld transceiver, so I scavenged a bulb from an old string of Christmas tree lights and hooked it up to my Yaesu FT-60. This video shows what happened next.

After I made the video, I checked the specs on the FT-60 and found that the transmit power settings are: 5.0 W (High) / 2.0 W (Middle) / 0.5 W (Low). In the video, I said the middle setting was one half watt, which is incorrect.

I checked the SWR on the light bulb and found it to be 2.7. I was not worried about damaging the handheld radio because they are designed to work into crummy antennas such as the standard rubber duck.

I hope you enjoyed this fun experiment. Sorry about the amateurish video quality…I just shot it with my iPhone and did some simple editing.

73 Bob K0NR

The post HT and Light Bulb Load appeared first on The KØNR Radio Site.

On some SOTA summits that are established radio sites, there can be significant RFI on 2 meters. I recently wrote about that here: RFI on SOTA Summits. There have also been discussions from time to time among VHF SOTA activators on which handheld transceiver (HT) has the most robust receiver for use in high RF environments. (Hint: a Baofeng is not going to be your best choice.)

This led me to an excellent web page by Razvan/YO9IRF that tabulates the receiver performance of HTs as measured in the ARRL lab. This is arguably the most objective look at HT performance out there. You can do a sort on a particular parameter and see which models are best.

Probably the parameter to start with is wide 3rd-order intermodulation on the 2-meter band. (I am going to ignore the 70 cm performance because most VHF SOTA contacts are on 2 meters.) The wide 3rd-order intermod performance relates to interference rejection from outside the amateur band.

Here are the best performing HTs for this parameter. (Go to the website directly to see other models listed.)

Interestingly, the Icom IC-V8 jumps to the top of the list. This is an older single-band 2m radio…and I happen to have one hiding somewhere in the basement. I am a bit surprised there are two Wouxun radios near the top of the list but they performed well.  No surprise that the Yaesu FT-60 shows up…it seems to be well-regarded by SOTA activators.

The narrow 3rd-order intermod performance relates to the receiver performance inside the amateur band. Sorting based on that parameter shows these radios at the top:

The Kenwood TH-22AT takes the top position, followed by the Yaesu FT-10R, both older single-band radios. The general trend here is that some of the older radios, especially single-band rigs, have better front end filtering. Newer radios tend to include reception of a wider range of frequencies outside the ham band and have receiver front ends that are correspondingly more open. The Radio Shack HTX-202 gets a lot of positive comments from the SOTA crowd and is on the shortlist.  Again, the well-regarded FT-60 makes the list.

Let’s check a few of my favorite HTs to see how they rate.

My usual SOTA handheld is the Yaesu FT-1DR. The wide 3rd-order intermod is 73 dB, or 12 dB worse than the FT-60 (85 dB). For narrow 3rd-order intermod, the FT-1DR is 58 dB vs 67 dB for the FT-60. This matches my impression that the FT-1DR does OK for most summits but is not the best radio for high RF environments.

Another radio to consider is the Yaesu FT-4XR. I often have this radio on at the house but I don’t use it for SOTA. This radio uses the same receiver IC as the Baofeng UV-5R but has better input filtering. The wide 3rd-order intermod is only 63 dB and the narrow 3rd-order is 61 dB (about the same as the FT-1DR).  The table does not list any Baofeng radios but I would expect them to perform worse than the FT-4XR.

Regular readers of this blog know that I use a Yaesu FT-90 mini-mobile transceiver for most SOTA activations. I looked up the ARRL tests on it. The wide and narrow 3rd-order intermod are 85 dB and 65 dB respectively, not better than the best handhelds but near the top. My experience is that the FT-90 receiver is better than my FT-60 and FT-1DR, consistent with the ARRL lab measurements.

Another radio of interest is the Yaesu FT-818, which the ARRL measured as 96 dB (wide 3rd-order intermod) and 72 dB (narrow 3rd-order intermod) on the 2m band.  This puts the FT-818 at the top of the list with the best handhelds. Actually, I would have expected it to be even better, far superior to an HT, but apparently not.

So I need to dig out that old Icom IC-V8 that is hiding in the basement. It may be a good piece of equipment to have along on SOTA activations.

73 Bob K0NR

The post Which HT For High RF SOTA? appeared first on The KØNR Radio Site.

One thing to watch out for when doing SOTA activations is the presence of strong Radio Frequency Interference (RFI) on some peaks. The typical scenario is that the summit is also an established radio site with transmitters that interfere with your ham radio operations.

I use the VHF/UHF bands for SOTA, so I am writing from that perspective. My impression is that HF interference is much less likely because these radio sites don’t usually have any HF transmitters. However, they may have broadband noise sources such as networking equipment, power line arcing or switching power supplies that can create problems on HF. Anyway, this post is focused on 2 meters and higher bands.

In my experience, the transmitters at radio sites may include land mobile repeaters (VHF or UHF), NOAA Weather (162.xx MHz), TV/FM broadcast stations and mobile wireless (cellular) systems. The TV/FM broad stations are really bad news because they run a crapton of RF power.

The worst summit I have encountered is Sandia Crest (W5N/SI-001) near Albuquerque, NM. See trip report here. They even have a sign in the parking lot to warn you that the RFI may wipe out your car’s keyless remote.

Some other notable RFI-heavy SOTA summits are Monarch Ridge South (W0C/SP-058), Squaw Mountain (W0C/PR-082), Terry Peak (W0D/NW-002), and Greentop (W4T/SU-076).

In a high RFI environment, your radio receiver gets overloaded such that you can’t hear stations calling you but they can hear you just fine. This results in the SOTA activator calling and calling while the chasers get frustrated that the activator never hears their call. Not good. It may not be obvious that this is happening. This blocking of the receiver may come and go, depending on which transmitters happen to be active.

Mitigation Strategies

There are a few things that you can do to deal with the RFI:

Move Away From The Source

Probably the first thing to try is just moving away from the source of interference. This may mean moving away from the highest point on the summit but it may be better overall to give up a few feet of elevation to not have the interference. You’ll need to stay in the activation zone to be a legitimate SOTA activation.

Use A Better Radio

Some radios are better than others when it comes to receiver performance including the ability to reject unwanted signals. The low cost radios from China (Baofeng or similar) generally have lousy receivers so they are a poor choice for operating from an RFI-intense summit. Many people report better results with the Yaesu FT-60, a solid performer. Commerical radios from Motorola are even more robust. I’ve been using a small mobile radio for SOTA (Yaesu FT-90) which outperforms most handheld radios.

Change Your Antenna

Using a directional antenna can help…just point it away from the source of the interference.  Oddly enough, using a worse performing antenna can help improve your ability to communicate. For example, a rubber duck antenna on a handheld radio will allow less of the interfering signal to get into your receiver which may improve your ability to receive. As long as the antenna is “good enough” to complete the radio contact, it may be the way to go. One trick I’ve used is to deploy two radios, one for receive with a crummy antenna and the other for transmit with a better antenna. That way, you still radiate a stronger signal while reducing the interference into the receiver.

Use A Bandpass Filter

You can insert a filter into your antenna feedline to reduce the interfering signal. The best approach is to use a bandpass filter that passes the frequency you are operating on but attenuates other signals.  SOTABeams offers a compact bandpass filter for the 2m band. (Note that it has a 5W power rating which is fine for handheld radios but not more powerful transceivers.) DCI Digital Communications offers higher power filters but they are much larger in size.

Change Frequency

Sometimes a small change in frequency might help a bit if the interference is limited to certain frequencies. Another tip is to try another band. That is, if you are getting interference on 2 meters, you may find that the 70 cm band is better. Or vice versa. It all depends on the transmitters at the site.

73 Bob K0NR

The post RFI on SOTA Summits appeared first on The KØNR Radio Site.

Congratulations to my wonderful spouse and favorite hiking partner, Joyce/K0JJW, for achieving Mountain Goat status for Summits On The Air (SOTA).

On August 10th, she reached 1000 activator points while activating Pikes Peak (W0C/FR-004).  She had quite the pileup on 146.55 MHz.  Her best DX for the day was WY7ATH near Cheyenne, WY at a distance of 167 miles. Not bad!

Early on, she always hiked with me on SOTA activations but didn’t start pursuing activator points until the middle of 2017. All of her SOTA contacts have been on the VHF/UHF bands, lots of 2m FM along with 2m SSB, 70 cm and 23 cm FM.

Joyce has activated 181 summits, 112 unique in 19 associations.
She is the second female Mountain Goat in Colorado (after Lynn/KC0YQF) and is the eighth female goat in North America.

73 Bob K0NR

The post New SOTA Mountain Goat: Joyce/K0JJW appeared first on The KØNR Radio Site.

The QSO Today Ham Expo is an exciting event that takes the fun of an amateur radio convention online!

Congrats and thanks to Eric/4Z1UG who conceived the idea and took the initiative to make it happen.

I was pleased to participate in the event, talking about Having Fun With VHF. In case you missed it, here is the video of my presentation.

Slides are here: Having Fun With VHF – Bob K0NR slides

73 Bob K0NR

The post QSO Today Ham Expo: Having Fun With VHF appeared first on The KØNR Radio Site.

I often get asked questions about the band plan for 2 meters (144 to 148 MHz). Usually, this is about choosing a suitable simplex frequency, because the repeater frequencies are already coordinated and visible.

I’ve written about 2m band plans before. This article attempts to cover the topic in a way that applies to all of the US. This is actually a challenge because VHF/UHF band plans are regional in nature.

What Frequency Do I Use On 2 Meters?

I also wrote this article which is specific to the state of Colorado.

It is always best to check your local VHF band plan, usually supplied by the frequency coordinating body for your area. Typically, their main focus is coordinating repeaters but simplex frequencies are also listed.  Most frequency coordinating bodies kind of follow the ARRL 2m band plan, while adapting it for local use.

Channel Spacing: 15 kHz or 20 kHz

A big issue for the 2-meter band is that some areas have adopted a 15-kHz channel spacing while others use a 20-kHz channel spacing.  A typical FM signal is about 16 kHz wide, so the 15 kHz channel spacing is a bit tight but does allow for more channels (resulting in more adjacent channel interference issues). The 20-kHz spacing is “cleaner” but with fewer channels.

This map from the ARRL web site shows the channel spacing in use across the various states.

The channel spacing is driven by factors associated with repeater coordination, and simplex usage tends to adopt the same spacing. (There is no technical reason that simplex has to use the same channel spacing as the repeaters but that’s what usually happens.)

Some repeater coordinating organizations have done a good job of prescribing FM simplex frequencies. The Colorado 2m band plan (called the Frequency Use Plan) lists each simplex frequency individually.  The Illinois Repeater Association uses a similar approach: Illinois 2m Band Plan. The Southeastern Repeater Association (SERA) 2m band plan is also very specific. Note that the SERA band plan indicates that some of the usual 2m simplex frequencies may be used as repeater pairs — an example of a local decision on frequency use.

The Arizona 2m band plan shows a range of frequencies to be used for FM simplex, such as 146.400 – 146.600 MHz along with a note that says the Even 20 kHz Frequencies should be used. So that means the preferred simplex frequencies in this range are 146.40, 146.42, 146.44, 146.46, 146.48, 146.50, 146.52, 146.54, 146.56, 146.58 and 146.60 MHz. Some repeater coordinating bodies just give the frequency segment allocated to FM simplex and don’t mention the channel spacing. And some organizations don’t say anything about FM simplex so you have to figure them out on your own.

Recommendations

So what do we make of all of this? When it comes to 2m FM simplex frequencies, try to find your local band plan. If it recommends 2m FM simplex frequencies, then follow that guidance.

If that doesn’t work, look at the map above to determine if your state uses 15 kHz or 20 kHz spacing. Then follow the guidance in the HamRadioSchool.com article: What Frequency Do I Use on 2 Meters?

In all cases, remember that these are shared frequencies so you need to cooperate with other radio hams. If you bump into existing activity, go ahead and try another frequency. There are usually plenty of quiet simplex channels around.

The one simplex frequency that everyone does seem to agree on is the National Simplex Calling Frequency: 146.52 MHz. For some thoughts on how to use that frequency see: The Use of 146.52 MHz.

I do think that frequency coordination bodies would be wise to provide guidance on simplex channels. This is not frequency coordination but it helps the amateur radio community be more effective in using the spectrum.

73 Bob K0NR

The post Simplex Channel Confusion on 2 Meters appeared first on The KØNR Radio Site.

McQuaid Butte (W0C/SP-019) is a 9043-foot mountain near our cabin in Park County. Joyce/K0JJW and I activated it for Summits On The Air (SOTA) way back in 2013 but for some reason, we had not been back to it. The access road (Salt Creek Road, FS 435) is gated closed from January 1 to June 15 to protect wildlife habitat, so I suppose that is a factor.

Today, we decided to make a return trip to the summit and activate it on VHF/UHF. I remembered that Salt Creek Road can turn into a muddy mess but today it was dry and easily drivable with most vehicles. Salt Creek Road is accessed from Highway 285, south of Fairplay but north of Antero Junction.

There is a good parking spot shown on the map above at 38.95791, -106.00790. A trail begins here, heading east. It used to be 4WD road but it is now closed to motor vehicles. This trail/road heads east and then curves to the north and eventually disappears. About that time, you’ll encounter a fence that needs to be crossed as you make your way towards the summit (approaching from the west). There are pieces of a trail here and there but its mostly bushwacking up the side of the summit. In places, there is substantial downed timber that can be stepped over and around but its mildly annoying.

Our route turned out to be 1.3 miles one way with 650 vertical feet. We both quickly made enough QSOs to qualify for activator points, working W0BV, KD0MRC, K0MGL, WZ0N on 2m FM (and some on 70 cm). The weather was excellent, resulting in a fun SOTA activation in the Pike National Forest.

We will probably return again to this summit because it’s a nice hike that is easy to get to from our cabin.  It would also be a great choice for someone passing through on Highways 24 or 285.

73 Bob K0NR

The post McQuaid Butte SOTA appeared first on The KØNR Radio Site.